0.6.0

Enhancements

• VariadicArgument now supports an optional validator.
• Adds support for variadic options, allowing the user to repeat options to
  provide additional values.
  #37
• Argument descriptions are now printed in command help.
  #33
• Default option and flag default values will now be shown in help output.
  Only default option types of String and Int are currently supported in help output.
  #34

Bug Fixes

• VaradicArgument has been renamed to VariadicArgument.